#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<string>
using namespace std;

class Solution {
public:
    int findLUSlength(string a, string b)
    {
        int len_a = a.size();
        int len_b = b.size();
        if (len_a != len_b)
            return max(len_a, len_b);
        int i;
        for (i = 0; i < len_a; i++)
        {
            if (a[i] != b[i])
                return len_a;
        }
        return -1;
    }
};